Optical element driving mechanism

ABSTRACT

An optical element driving mechanism is provided. The optical element driving mechanism includes a movable part and a fixed part. The movable part holds an optical element with an optical axis and moves relative to the fixed part. The fixed part includes a bottom unit, which is integrally formed. The bottom unit includes a base member, a circuit member, and a driving coil assembly. The driving coil assembly is electrically connected to the circuit member. The circuit member and the driving coil assembly are located at the base member. The driving coil assembly includes a connection wire, a plurality of first driving coils, and a plurality of second driving coils. The first driving coils are connected via the connection wire. The second driving coils are located between the first driving coils and the circuit member. When viewed along a direction that is perpendicular to the optical axis, the second driving coils partially overlap the connection wire.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims priority of U.S. Provisional PatentApplication No. 62/697,621, filed on Jul. 13, 2018 and CN ApplicationNo. 201910585143.6, filed on Jul. 1, 2019, which are incorporated byreference herein in their entirety.

BACKGROUND OF THE DISCLOSURE Field of the Disclosure

The present disclosure relates to a driving mechanism, and moreparticularly to an optical element driving mechanism.

Description of the Related Art

As technology has developed, many electronic devices (such as tabletcomputers and smartphones) are equipped with optical element drivingmechanisms. One or more optical elements driven by the optical elementdriving mechanisms can capture images and record videos.

In general, an optical element driving mechanism may include a case, aholder, a magnet, a coil, a printed circuit board, and a bottom. Theseelements are stacked together. However, the overall height of theoptical element driving mechanism is increased because of thearrangement of these elements. Additionally, the trend in electronicdevices is toward miniaturization, and especially reductions in theheight of electronic devices. This is done for convenience. That is, theheight of optical element driving mechanisms installed in electronicdevices has to be reduced as well.

Therefore, how to reduce the height of an optical element drivingmechanism is a topic worth exploring and a problem worth solving.

BRIEF SUMMARY OF THE DISCLOSURE

According to some embodiments of the disclosure, an optical elementdriving mechanism is provided. The optical element driving mechanismincludes a movable part and a fixed part. The movable part holds anoptical element with an optical axis and moves relative to the fixedpart. The fixed part includes a bottom unit which is integrally formed.The bottom unit includes a base member, a circuit member, and a drivingcoil assembly. The circuit member and the driving coil assembly arelocated at the base member. The driving coil assembly is electricallyconnected to the circuit member. The driving coil assembly includes aconnection wire, a plurality of first driving coils, and a plurality ofsecond driving coils. The first driving coils are connected to eachother via the connection wire. The second driving coils are locatedbetween the first driving coils and the circuit member. When viewedalong a direction that is perpendicular to the optical axis, the seconddriving coils partially overlap the connection wire. The number of turnsin each of the first driving coils is different than the number of turnsin each of the second driving coils. The profile of the driving coilassembly is substantially rectangular or elliptical, and the drivingcoil assembly includes a concave portion. The width of the connectionwire is greater than the width of each one of the first driving coils.The driving coil assembly and the circuit member are electricallyconnected at an electrical connection point. The electrical connectionpoint is located at the base member and are is exposed from the bottomunit. In a direction that is parallel to the optical axis, the size ofthe driving coil assembly is greater than the size of the circuit member

The base member further includes a first base and a second base. Thefirst base is formed on the second base. The hardness of the first baseis different than the hardness of the second base. The driving coilassembly is located at the first base, and the circuit member is locatedat the second base. The top surface of the circuit member is in contactwith the bottom surface of the first base. The bottom surface of thecircuit member is in contact with the second base. The top surface ofthe circuit member is parallel to the bottom surface of the circuitmember. The top surface of the circuit member and the top surface of thesecond base are in contact with the bottom surface of the first base.Alternatively, the top surface of the driving coil assembly is incontact with the first base. The bottom surface of the driving coilassembly is in contact with the top surface of the second base. The topsurface of the driving coil assembly is parallel to the bottom surfaceof the driving coil assembly. The bottom surface of the driving coilassembly and the bottom surface of the first base are in contact withthe top surface of the second base.

The optical element driving mechanism further includes an electronicelement disposed in the base member. The electronic element may be achip that is not packaged. When viewed along a direction that isperpendicular to the optical axis, the driving coil assembly partiallyoverlaps the electronic element. A portion of the circuit member isdisposed between the driving coil assembly and the electronic element.

The optical element driving mechanism further includes an elasticelement. The movable part is elastically connected to the fixed part viathe elastic element. The bottom unit includes an elastic elementconnection portion. The elastic element passes through the elasticelement connection portion. The elastic element is electricallyconnected to the elastic element connection portion. The elastic elementconnection portion includes a first perforation and a secondperforation. The size of the first perforation is different than thesize of the second perforation.

The fixed part further includes a case. A plurality of straight lineportions and a plurality of curved line portions are formed between thecase and the bottom unit. The straight line portions are connected viathe curved line portions. The width of each one of the curved lineportions is greater than the width of each one of the straight lineportions.

The bottom unit further includes a support surface. The bottom unit isconnected to the case at the support surface, and the support surfaceincludes a metal layer. When viewed along a direction that isperpendicular to the optical axis, the metal layer partially overlapsthe circuit member or the driving coil assembly. The circuit memberincludes an external electrical connection surface which isperpendicular to the optical axis, and the external electricalconnection surface is exposed from the bottom unit.

The optical element driving mechanism further includes a strengtheningmember located at the base member and may be integrally formed with thebase member. When viewed along a direction that is perpendicular to theoptical axis, the strengthening member partially overlaps the drivingcoil assembly. The strengthening member and the driving coil assemblyare electrically independent. When viewed along a direction that isparallel to the optical axis, the base member partially overlaps thestrengthening member and the circuit member. The strengthening member isa plate structure including a grid-shaped structure, a honeycomb-shapedstructure, or a concentric circle-shaped structure. The strengtheningmember is made of a metal material. When viewed along a direction thatis perpendicular to the optical axis, the height of the strengtheningmember is the same as the height of the driving coil assembly. Thestrengthening member is disposed between the optical element and thedriving coil assembly.

According to some embodiments of the disclosure, an optical elementdriving mechanism is provided. The optical element driving mechanismincludes a fixed part, a movable part, and a driving assembly. Themovable part holds an optical element with an optical axis and movesrelative to the fixed part. The driving assembly drives the movable partto move relative to the fixed part. The driving assembly includes amagnetic element and a driving coil assembly. The driving coil assemblyincludes a connection wire, a plurality of first driving coils, and aplurality of second driving coils. The positions of the first drivingcoils correspond to the magnetic element. The first driving coils arelocated between the magnetic element and the second driving coils. Thefirst driving coils are connected to each other via the connection wire.When viewed along a direction that is perpendicular to the optical axis,the second driving coils partially overlap the connection wire.

BRIEF DESCRIPTION OF THE DRAWINGS

Aspects of the present disclosure are best understood from the followingdetailed description when read with the accompanying figures. It shouldbe noted that, in accordance with the standard practice in the industry,various features are not drawn to scale. In fact, the dimensions of thevarious features may be arbitrarily increased or reduced for clarity ofdiscussion.

FIG. 1 is a perspective view of an optical element driving mechanism andan optical element in accordance with some embodiments of thisdisclosure.

FIG. 2A is an exploded view of the optical element driving mechanism inFIG. 1.

FIG. 2B is a cross-sectional view illustrated along line A-A in FIG. 1.

FIG. 3 is an exploded view of a bottom unit.

FIG. 4 is a top view of the bottom unit.

FIG. 5 is a schematic view of the bottom unit in a cross-sectional view.

FIG. 6 is an exploded view of a case and a base member.

FIGS. 7A-7E are flow charts of the process of manufacturing the bottomunit.

FIG. 8 is a configuration of the bottom unit and an electronic elementin a cross-sectional view.

FIG. 9 is a configuration of the bottom unit and the electronic elementin a cross-sectional view.

FIG. 10 is a perspective view of the bottom unit and an elastic element.

FIG. 11 is a schematic view of an elastic element connection portion ina cross-sectional view.

FIG. 12 is a bottom view of a portion of the optical element drivingmechanism.

FIG. 13 is a bottom view of the optical element driving mechanism.

FIG. 14 is a top view of the bottom unit and a strengthening member.

FIG. 15 is a schematic view of the strengthening member.

DETAILED DESCRIPTION OF THE DISCLOSURE

The following disclosure provides many different embodiments, orexamples, for implementing different features of the provided subjectmatter. Specific examples of components and arrangements are describedbelow to simplify this disclosure. These are, of course, merely examplesand are not intended to be limiting. For example, the formation of afirst feature “on” or “above” a second feature in the description thatfollows may include embodiments in which the first and second featuresare formed in direct contact, and may also include embodiments in whichadditional features may be formed between the first and second features,such that the first and second features may not be in direct contact.The ordinal terms such as “first”, “second”, etc., used in thedescription and in claims do not by themselves connote any priority,precedence, or order of one element over another, but are used merely aslabels to distinguish one element from another element having the samename. In addition, in different examples of this disclosure, symbols oralphabets may be used repeatedly.

Furthermore, spatially relative terms, such as “above” and the like, maybe used herein for ease of description to describe one element orfeature's relationship to another element or feature as illustrated infigures. The spatially relative terms are intended to encompassdifferent orientations of the device in use or operation in addition tothe orientation depicted in figures. The apparatus may be otherwiseoriented (rotated 90 degrees or at other orientations) and the spatiallyrelative descriptors used herein may likewise be interpretedaccordingly.

The embodiments of this disclosure are described with the drawings.

FIG. 1 is a perspective view of an optical element driving mechanism 1and an optical element 2 in accordance with some embodiments of thisdisclosure. FIG. 2A is an exploded view of the optical element drivingmechanism 1 in FIG. 1. The optical element driving mechanism 1 includesa fixed part P1 and a movable part P2. The movable part P2 movesrelative to the fixed part P1 and holds the optical element 2 with anoptical axis O. The optical axis O is defined as a virtual axis passingthrough the center of the optical element 2.

It should be noted that when the optical element 2, the optical elementdriving mechanism 1, and a photosensitive element (not shown, such as acoupling photosensitive detector, CCD) are aligned, the optical axis Oof the optical element 2 also passes through the center of the opticalelement driving mechanism 1. Even the optical element 2 is notillustrated in some drawings, the optical axis O is still illustratedfor clear illustration such as the features related to the opticalelement driving mechanism 1.

In this embodiment, the fixed part P1 includes a case 10, a frame 15,and a bottom unit 110 which is integrally formed. The movable part P2includes a holder 20, a coil 25, four magnetic elements 30, four elasticelements 40, and an electronic element 50. The elements or componentsmay be added or deleted according to requirements.

The case 10, the frame 15, and the bottom unit 110 of the fixed part P1are arranged along the optical axis O. The case 10 is located above theframe 15 and the bottom unit 110. The methods for connecting the case 10and the bottom unit 110 may be engagement, welding, or using aconductive resin material, etc. Other elements of the optical elementdriving mechanism 1, such as the movable part P2, may be accommodated inthe space formed by the combination of the case 10 and the bottom 110.The frame 15 includes four receiving holes 16 for receiving the fourmagnetic elements 30.

The holder 20 of the movable part P2 includes a hole 21 to hold theoptical element 2. A screw and corresponding threaded structure may beconfigured between the hole 21 and the optical element 2, so that theoptical element 2 may be affixed in the holder 20 better.

The holder 20 is not in direct contact with the case 10. The holder 20is not in direct contact with the bottom unit 110, either. In someembodiments, the holder 20 is held by one or more springs (not shown)elastically to restrict the range of movement of the holder 20.Therefore, when the optical element driving mechanism 1 moves or isimpacted by the environment, the holder 20 and the optical element 2therein are not damaged by colliding with the case 10 or the bottom unit110.

The coil 25 surrounds the holder 20, and the coil 25 is polygonal.Please refer to FIG. 2B to understand the configuration of the coil 25and the magnetic element 30. FIG. 2B is a cross-sectional viewillustrated along line A-A in FIG. 1. As shown in FIG. 2B, when acurrent is applied to the coil 25, a magnetic force is generated betweenthe coil 25 and the magnetic element 30 to drive the holder 20 and theoptical element 2 therein to move along a direction that is parallel tothe optical axis O, thereby achieving auto focus (AF).

The positions of the four magnetic elements 30 correspond to theposition of the driving coil assembly 130. When a current is applied tothe driving coil assembly 130, a magnetic force is generated between thedriving coil assembly 130 and the corresponding magnetic element 30 todrive the holder 20 and the optical element 2 therein to move along adirection that is perpendicular to the optical axis O, thereby achievingoptical image stabilization (OIS).

The movable part P1 and the fixed part P2 are elastically connected bythe four elastic elements 40. The four elastic elements 40 arerespectively disposed at the four corners of the bottom unit 110. Theelastic elements 40 have long strip-shaped structures, for example,columnar or linear, but are not limited thereto.

The electronic element 50 is disposed in the bottom unit 110, so thatspace may be saved and miniaturization is achieved. The electronicelement 50 may be a sensing element, a passive element, a drivingintegrated circuit (IC), such as capacitors, resistors, inductors, or achip this is not packaged.

In other embodiments of this disclosure, the movable part P2 furtherincludes a sensed object and a sensor (not shown). The sensed objectedis disposed close to the holder 20, and the position of the sensorcorresponds to the position of the sensed object. The sensed object maybe a magnetic element, such as a magnet. The sensor may be a giantmagnetoresistive effect sensor (GMR sensor), a tunnelingmagnetoresistive effect sensor (TMR sensor), etc. When the holder 20moves, the sensed object near the holder 20 moves as well, and themagnetic field of the sensed object changes. Additionally, the change ofthe magnetic field of the sensed object is detected by the sensor.Therefore, the position of the holder 20 may be known. Furthermore, theposition adjustment and the displacement control of the holder 20 may beconducted.

Next, please refer to FIG. 3 and FIG. 4 to clearly understand theconfiguration of the bottom unit 110 which is integrally formed. FIG. 3is an exploded view of the bottom unit 110. FIG. 4 is a top view of thebottom unit 110.

The bottom unit 110 includes a base member 120, a driving coil assembly130, and a circuit member 140. The driving coil assembly 130 iselectrically connected to the circuit member 140. The driving coilassembly 130 and the circuit member 140 are located at the base member120, so that the bottom unit 110 is integrally formed.

It should be noted that the term “integrally formed” as used herein doesnot mean that the base member 120, the driving coil assembly 130, andthe circuit member 140 are inseparably made of the same material. Theterm “integrally formed” as used herein means that after the bottom unit110 is manufactured, the base member 120, the driving coil assembly 130,and the circuit member 140 of the bottom unit 110 are physicallyconnected. The base member 120, the driving coil assembly 130, and thecircuit member 140 of the bottom unit 110 do not need to be assembled.Thus, the bottom unit 110 is defined as “integrally formed”. There is noneed to connect the base member 120, the driving coil assembly 130, andthe circuit member 140 of the bottom unit 110 by adhesion, welding, etc.Therefore, the process may be simplified, the complexity ofmanufacturing may be reduced, and/or the production cost may bedecreased.

The “height” of the element as described herein is defined as the lengthof the element that is parallel to the optical axis O for clearillustration. The demand for a thinner electronic device is increasing,and thus the height of the optical element driving mechanism 1 installedin the electronic device has to be reduced as well.

In general, the driving coil assembly may be embedded in the circuitboard. The circuit board and the bottom have to be connected by adhesionor welding, and the sum of the height of the circuit board and thebottom is about 0.85 mm. The height of the bottom unit is difficult tobe reduced in such a situation because each of the elements has itsminimum height limit. In this disclosure, the driving coil assembly 130and the circuit member 140 are located at the base member 120, and theheight of the integrally formed bottom unit 110 is about 0.5 mm. Theoverall height of the optical element driving mechanism 1 issignificantly reduced, and the optical element driving mechanism 1 maybe thinner.

The driving coil assembly 130 has a plurality of turns. A single wire ormultiple wires are wound in the same winding layer to form turns. Afterenough turns are formed in the same winding layer, other turns are woundin the next winding layer. Thus, multiple winding layers are formed.According to different designs or requirements, the driving coilassembly 130 may have a different number of winding layers. The windinglayers are usually even numbers, such as four layers or eight layers,but are not limited hereto. As shown in FIG. 3, in this embodiment, thedriving coil assembly 130 has four winding layers which are sequentiallyarranged along a direction that is parallel to the optical axis O,including a first winding layer L1, a second winding layer L2, a thirdwinding layer L3, and a fourth winding layer L4. The wires connectingthe first winding layer L1, the second winding layer L2, the thirdwinding layer L3, and the fourth winding layer L4 are not shown.

The driving coil assembly 130 includes two first driving coils 131, twosecond driving coils 132, two third driving coils 133, two fourthdriving coils 134, a connection wire 1311, and another connection wire1331. The first driving coils 131 are connected to each other via theconnection wire 1311, and the third driving coils 133 are connected toeach other via the connection wire 1331. It should be noted that, inFIG. 2A and FIG. 3, the connection wire 1331 is not shown in order toillustrate the connection wire 1311 clearly. The first driving coils 131and the third driving coils 133 are located at the second winding layerL2. The second driving coils 132 and the fourth driving coils 134 arelocated at the third winding layer L3. Therefore, when viewed in adirection that is perpendicular to the optical axis O, the third drivingcoils 133 partially overlap the first driving coils 131, and the fourthdriving coils 134 partially overlap the second driving coils 132.

As mentioned above, the driving coil assembly 130 drives the movablepart P2 to move along a direction that is perpendicular to the opticalaxis O. More specifically, the first driving coils 131 and the seconddriving coils 132 located on opposite sides drive the movable part P2 tomove along the X-axis. In contrast, the third driving coils 133 and thefourth driving coils 134 located on opposite sides drive the movablepart P2 to move along the Y-axis.

As shown in FIG. 4, the profile of the driving coil assembly 130 issubstantially rectangle-shaped. In other embodiments, the profile of thedriving coil assembly 130 is shaped substantially like an ellipse. Thedriving coil assembly 130 is provided with a concave portion 130Clocated at a position that is close to the optical element 2. Therefore,the accommodation space for the optical element 2 may be increased, anda larger optical element 2 may be installed in the optical elementdriving mechanism 1. The optical element driving mechanism 1 may be morepractical.

In the following text, only the structures and the configurationsregarding the first driving coils 131 and the second driving coils 132are described. It should be understood that the third driving coils 133and the fourth driving coils 134 also have similar structures andconfigurations.

FIG. 5 is a schematic view of the bottom unit 110 in a cross-sectionalview. For simplicity, the connection wire 1311 and the first drivingcoils 131 are drawn to be located on the same plane in FIG. 2A and FIG.3. However, in fact, as shown in FIG. 5, a portion of the connectionwire 1311 (the middle of the connection wire 1311 which is not adjacentto the first driving coils 131) is disposed at a side away from themagnetic element 30. When viewed along a direction that is perpendicularto the optical axis O, the second driving coils 132 partially overlapthe connection wire 1311. This configuration may reduce magneticinterference and enhance the magnetic driving force. Additionally, theconnection wire 1311 is taken out from the first driving coils 131, sothe number of turns in each of the first driving coils 131 is differentthan the number of turns in each of the second driving coils 132.

It should be clarified that the first driving coils 131 and the thirddriving coils 133 are not limited to be located at the second windinglayer L2. Similarly, the second driving coils 132 and the fourth drivingcoils 134 are not limited to be located at the third winding layer L3.Except for the winding layer that is closest to or farthest from themagnetic element 30, the first driving coils 131 may be located at anyof the other winding layers.

The magnetic force is inversely proportional to the square of thedistance. Compared to the other winding layers, the maximal magneticdriving force is generated in the winding layer of the driving coilassembly 130 that is closest to the magnetic element 30 (for example,the first winding layer L1 in this embodiment). To assure that thenumber of turns in the winding layer that is closest to the magneticelement 30 is enough for generating the maximal magnetic force, normallyno wire is taken out from the winding layer that is closest to themagnetic element 30. Therefore, the first driving coils 131 with theconnection wire 1311 taken out are not located in the winding layer thatis closest to the magnetic element 30 normally. The number of turns inthe winding layer that is closest to the magnetic element 30 may beassured. Additionally, a portion of the connection wire 1311 is disposedat a side away from the magnetic element 30 to reduce the magneticinterference, so the first driving coils 131 are not located at thewinding layer that is farthest from the magnetic element 30 (forexample, the fourth winding layer L4 in this embodiment) normally.

To sum up, as long as the second driving coils 132 are located betweenthe first driving coils 131 and the circuit member 140, and the fourthdriving coils 134 are located between the third driving coils 133 andthe circuit member 140, such a situation falls into the scope of thisdisclosure. Take an optical element driving mechanism with eight windinglayers as an example, the first driving coils 131 with the connectionwire 1311 taken out may be located at the third winding layer, and thesecond driving coils 132 may be located at the fifth winding layer.Alternatively, the first driving coils 131 with the connection wire 1311taken out may be located at the fourth winding layer, and the seconddriving coils 132 may be located at the seventh winding layer.Additionally, in various embodiments, the second driving coils 132partially overlap the connection wire 1311.

It should be noted that the resistance of the wire is inverselyproportional to the width of the wire. To reduce the resistance andenhance the structural strength of the wire, the width of the connectionwire 1311 may be designed to be greater than the width of the wire ofthe first driving coils 131 during the process of manufacturing thebottom unit 110. Compared to the first driving coils 131, there arefewer elements around the connection wire 1311. The connection wire 1311is strengthened to make sure the optical element driving mechanism 1 maybe operated normally.

The driving coil assembly 130 and the circuit member 140 areelectrically connected at an electrical connection point 135. Theelectrical connection point 135 is located at the base member 120 and isnot exposed from the bottom unit 110. Additionally, the driving coilassembly 130 is a multi-layer structure. The size of the driving coilassembly 130 is greater than the size of the circuit member 140 in adirection that is parallel to the optical axis O.

FIG. 6 is an exploded view of the case 10 and the base member 120. Thebase member 120 includes a first base 121 and a second base 122. Thefirst base 121 is formed on the second base 122. The second base 122includes a support surface 1221, and the bottom unit 110 is connected tothe case 10 at the support surface 1221. The support surface 1221 has ametal layer 1222.

As shown in FIG. 6, the driving coil assembly 130 is located at thefirst base 121, and the circuit member 140 is located at the second base122. Since the size of the driving coil assembly 130 is greater than thesize of the circuit member 140 in a direction that is parallel to theoptical axis O, the size T1 of the first base 121 is also greater thanthe size T2 of the second base 122. The driving coil assembly 130 iscovered by the first base 121, so that the driving coil assembly 130 isprotected by the first base 121. Similarly, the circuit member 140 maybe protected by the second base 122. This configuration may be changed.For example, the driving coil assembly 130 may be located at the secondbase 122, the circuit member 140 may be located at the first base 121,and the size of the second base 122 is greater than the size of thefirst base 121.

The hardness of the first base 121 and the second base 122 may be thesame or different. For example, when the hardness of the first base 121is greater than the hardness of the second base 122, it's beneficial forthe bendability of the second base 122 and the circuit member 140covered by the second base 122. When the hardness of the first base 121is less than the hardness of the second base 122, the structuralstrength of the first base 121 disposed on the second base 122 may beenhanced. Therefore, depending on requirements, the base member 120 maybe designed to satisfy the mechanical strength or bendability in orderto strengthen the structure of the optical element driving mechanism 1.

It should be emphasized that the first base 121 and the second base 122are manufactured at different stages in the manufacturing process, sothat the first base 121 and the second base 122 may be made of differentmaterials. FIGS. 7A-7E are flow charts of the process of manufacturingthe bottom unit 110. From the description, a person having ordinaryskill in the art may be able to understand how the bottom unit 110 ofthis disclosure is integrally formed without requiring further assembly.

FIG. 7A illustrates a substrate 115. FIG. 7B illustrates the substrate115 with the predetermined circuit structures after such processes asdielectric material D deposition, circuit layer (for example, copper)deposition, exposure, development, and etching. The predeterminedcircuit structure formed in FIG. 7B is the first winding layer L1 of thedriving coil assembly 130. Next, the processes of dielectric material Ddeposition, circuit layer deposition, exposure, development, etching arerepeated several times to obtain different predetermined circuitstructures (i.e., the second winding layer L2, the third winding layerL3, the fourth winding layer L4). The first base 121 is formed bydielectric material D deposition. After the first base 121 is formed,the circuit member 140 is formed on the first base 121. FIG. 7Cillustrates the substrate 115, the first base 121, and the circuitmember 140. As shown in FIG. 7C, the first winding layer L1, the secondwinding layer L2, the third winding layer L3, and the fourth windinglayer L4 are covered by the first base 121.

Next, the electronic element 50 is mounted on the circuit member 140,and the deposition of the second base 122 is carried out. FIG. 7Dillustrates the bottom unit 110 after the deposition of the second base122 is accomplished. It should be noted that the circuit member 140 isformed at the interface of the first base 121 and the second base 122.The substrate 115 is then removed, a first perforation 411 and a secondperforation 412 are cut out, and the metal layer 1222 is formed. Thebottom unit 110 is then placed upside down. FIG. 7E illustrates thebottom unit 110 after the manufacturing process. The contents of thefirst perforation 411, the second perforation 412, and the metal layer1222 are described in detail below.

The area and the position of the support surface 1221 are not limited tothe embodiment shown in FIG. 6. For example, when viewed in a directionthat is parallel to the optical axis O, the first base 121 may becontinuously surrounded by the support surface 1221. Therefore, when thecase 10 is connected to bottom unit 110 at the support surface 1221, thefirst base 121 is completely surrounded by the case 10, thereby reducingthe possibility of matter or dust entering the optical element drivingmechanism 1. Alternatively, the shape of the first base 121 may beadjusted. For example, the four corners of the first base 121 may bereduced inwardly by a distance, so that the case 10 may be easier to beconnected to the bottom unit 110 at the support surface 1221.

The support surface 1221 and the bottom unit 110 may be strengthened bythe metal layer 1222. From the description of FIGS. 7A-7E, thedeposition of the metal layer 1222 and the circuit member 140 aresimultaneously conducted. Therefore, when viewed along a direction thatis perpendicular to the optical axis O, the metal layer 1222 partiallyoverlaps the circuit member 140. Additionally, the metal layer 1222 maybe simultaneously deposited with any of the winding layers of thedriving coil assembly 130 at the same step. In such a situation, themetal layer 1222 partially overlaps the driving coil assembly 130. Themanufacturing process may be simplified by simultaneously depositing themetal layer 1222 and the circuit member 140 or simultaneously depositingthe metal layer 1222 and any of the winding layers of the driving coilassembly 130. The production efficiency of the bottom unit 110 isincreased. Miniaturization of the bottom unit 110 and the opticalelement driving mechanism 1 in a direction that is parallel to theoptical axis O is achieved.

FIG. 8 is a configuration of the bottom unit 110 and the electronicelement 50 in a cross-sectional view, and FIG. 8 is simplified from FIG.7E. In this embodiment, the electronic element 50 is located at thesecond base 122, and the electronic element 50 may be completelyembedded in the second base 122 and not exposed from the bottom unit110, so that the electronic element 50 may be protected. Since the sizeof the driving coil assembly 130 located at the first base 121 is notaffected or restricted by the electronic element 50 located at thesecond base 122, the size of the driving coil assembly 130 may beadjusted to make sure that the magnetic force is enough for driving theoptical element driving mechanism 1.

The circuit member 140 is located at the second base 122. Morespecifically, the circuit member 140 is in contact with the interface ofthe first base 121 and the second base 122. A portion of the circuitmember 140 is disposed between the driving coil assembly 130 and theelectronic element 50. The top surface 140 a of the circuit member 140is in contact with the bottom surface 121 b of the first base 121, andthe bottom surface 140 b of the circuit member 140 is in contact withthe second base 122. The top surface 140 a is parallel to the bottomsurface 140 b. Additionally, the top surface 140 a of the circuit member140 and the top surface 122 a of the second base 122 are in contact withthe bottom surface 121 b of the first base 121.

In other embodiments of this disclosure, the circuit member 140 islocated at the first base 121 and is in contact with the interface ofthe first base 121 and the second base 122. In such a situation, thebottom surface 140 b of the circuit member 140 and the bottom surface121 b of the first base 121 are in contact with the top surface 122 a ofthe second base 122.

FIG. 9 is a configuration of the bottom unit 110 and the electronicelement 50 in a cross-sectional view according to some embodiments ofthis disclosure. In this embodiment, the electronic element 50 islocated at the first base 121. When viewed along a direction that isperpendicular to the optical axis O, the driving coil assembly 130partially overlaps the electronic element 50. Additionally, theelectronic element 50 may be completely embedded in the first base 121and not exposed from the bottom unit 110, so that the electronic element50 may be protected.

In this embodiment, the driving coil assembly 130 is located at thefirst base 121. In some embodiments, the driving coil assembly 130 maybe in contact with the interface of the first base 121 and the secondbase 122. In such a situation, the top surface 130 a of the driving coilassembly 130 is in contact with the first base 121, and the bottomsurface 130 b of the driving coil assembly 130 is in contact with thetop surface 122 a of the second base 122. The top surface 130 a isparallel to the bottom surface 130 b. Additionally, the bottom surface130 of the driving coil assembly 130 and the bottom surface 121 b of thefirst base 121 are in contact with the top surface 122 a of the secondbase 122.

In other embodiments of this disclosure, the driving coil assembly 130is located at the second base 122 and in contact with the interface ofthe first base 121 and the second base 122. In such a situation, the topsurface 130 a of the driving coil assembly 130 and the top surface 122 aof the second base 122 are in contact with the bottom surface 121 b ofthe first base 121.

To sum up, since the circuit member 140 or the driving coil assembly 130is located at the interface of the first base 121 and the second base122, no additional space is required to accommodate the circuit member140 or the driving coil assembly 130. The processes may be simplifiedand miniaturization may be achieved.

FIG. 10 is a perspective view of the bottom unit 110 and the elasticelement 40. The bottom unit 110 has four elastic element connectionportions 41. The elastic element 40 passes through the elastic elementconnection portion 41. The elastic element 40 is electrically connectedto the elastic element connection portion 41. Therefore, no additionalwires are required to be disposed at the end of the elastic element 40.The configuration of the circuit structure may be simplified.Additionally, the body of the elastic element 40 has a longer extendableor shortened portion.

FIG. 11 is a schematic view of the elastic element connection portion 41in a cross-sectional view. The elastic element connection portion 41includes the first perforation 411 and the second perforation 412. Thefirst perforation 411 is closer to the movable part P2 than the secondperforation 412. The size of the first perforation 411 is different thanthat of the second perforation 412. In this embodiment, since theelastic element 40 is electrically connected to the elastic elementconnection portion 41 by welding or the like at the second perforation412, the first perforation 411 is smaller than the second perforation412. Therefore, it's advantageous for the elastic element 40 to beconnected to the bottom unit 110. The assembling efficiency of theelastic element 40 may be enhanced.

To protect the elastic element connection portion 41 from oxidation andto enhance the durability of the elastic element connection portion 41,a first plated layer (not shown) and a second plated layer (not shown)may be plated on the elastic element connection portion 41. The secondplated layer is plated over the first plated layer, so that the firstplated layer is located between the elastic element connection portion41 and the second plated layer. The second plated layer may be made of ametal material which is unlikely to be oxidized. For example, the firstplated layer may include nickel (Ni), and the second plated layer mayinclude gold (Au). The elastic element 40 may be electrically connectedto the elastic element connection portion 41 via the first plated layerand the second plated layer.

FIG. 12 is a bottom view of a portion of the optical element drivingmechanism 1, in which the case 10 is connected to the bottom unit 110.FIG. 12 illustrates one of the four corners of the optical elementdriving mechanism 1. In each corner, two straight line portions 11 and acurved line portion 12 are formed in the space between the case 10 andthe bottom unit 110. The straight line portions 11 are connected via thecurved line portion 12. As shown in FIG. 12, the width D2 of the curvedline portion 12 is greater than the width D1 of the straight lineportion 11. It should be noted that the size of the corners of theoptical element driving mechanism 1 is not easy to control. When thecase 10 is connected to the bottom unit 110, the deviation of assemblingmay possibly occur. By such design, the deviation of assembling may beprevented. Furthermore, an adhesive may be filled into the straight lineportion 11 and/or the curved line portion 12, as needed, to increase thestructural strength of the optical element driving mechanism 1 and toreduce the possibility of matter or dust entering the optical elementdriving mechanism 1.

FIG. 13 is a bottom view of the optical element driving mechanism 1. Thecircuit member 140 has an external electrical connection surface 141perpendicular to the optical axis O. The external electrical connectionsurface 141 is exposed from the bottom unit 110. An electronic part oran electronic element may be mounted on the external electricalconnection surface 141 by surface mount technology (SMT), therebyreducing the volume of the optical element driving mechanism 1. In otherembodiments, the circuit member 140 has an external electricalconnection surface parallel to the optical axis O. An external circuitor an external element may be electrically connected to the externalelectrical connection surface by welding or the like. Alternatively, theexternal electrical connection surface may be made of a flexiblematerial such as a flexible printed circuit (FPC). Therefore, theexternal electrical connection surface may be bent to be assembled. Thepossibility of connecting the external electrical connection surface tothe external circuit or the external element may be increased, and theassembling efficiency may be further enhanced.

FIG. 14 is a top view of the bottom unit 110 and a strengthening member150. Since the height of the optical element driving mechanism 1 isthin, the elements therein may be damaged when the optical elementdriving mechanism 1 functions or the optical element driving mechanism 1is affected by the environment. For example, breakage of the wire of thedriving circuit assembly 130 may occur.

To strengthen the structural strength of the optical element drivingmechanism 1, the strengthening member 150 may be provided. Thestrengthening member 150 is located at the base member 120 and may beintegrally formed with the base member 120. When viewed along adirection that is parallel to the optical axis O, the base member 120partially overlaps the circuit member 140 and the strengthening member150. To prevent a short circuit, the strengthening member 150 and thedriving coil assembly 130 are electrically independent.

When viewed along a direction that is perpendicular to the optical axisO, the strengthening member 150 partially overlaps the driving coilassembly 130. Therefore, when the optical element driving mechanism 1moves or a shock occurs, the pressure that the driving coil assembly 130borne may be dispersed by the strengthening member 150. The durabilityof the bottom unit 110 may be enhanced, and the overall structure of thebottom unit 110 may be protected. In some embodiments, the height of thestrengthening member 150 is the same as the height of the driving coilassembly 130.

The strengthening member 150 is a plate structure, including a pluralityof regular shape. FIG. 15 is a schematic view of the strengtheningmember 150. In this embodiment, the strengthening member 150 includes ahoneycomb-shaped structure. However, the strengthening member 150 mayinclude a grid-shaped structure, a concentric circle-shaped structure orother shape depending on requirements of the user or the types of theoptical element driving mechanism 1. Additionally, the strengtheningmember 150 may be made of a metal material such as copper.

Based on this disclosure, the height of the optical element drivingmechanism may be reduced by the bottom unit which is integrally formed.Miniaturization may be achieved. Furthermore, the manufacturing processmay be simplified and the production cost may be reduced. The opticalelement driving mechanism of this disclosure may still achieve theoriginal effects while being miniaturized. Also, the structural strengthof the optical element driving mechanism may be increased by thestrengthening member.

The foregoing outlines features of several embodiments so that thoseskilled in the art may better understand the aspects of this disclosure.Those skilled in the art should appreciate that they may readily usethis disclosure as a basis for designing or modifying other processesand structures for carrying out the same purposes and/or achieving thesame advantages of the embodiments introduced herein. Those skilled inthe art should also realize that such equivalent constructions do notdepart from the spirit and scope of this disclosure, and that they maymake various changes, substitutions, and alterations herein withoutdeparting from the spirit and scope of this disclosure.

In addition, the scope of this disclosure is not limited to the specificembodiments described in the specification, and each claim constitutes aseparate embodiment, and the combination of various claims andembodiments are within the scope of the disclosure.

What is claimed is:
 1. An optical element driving mechanism, comprising:a movable part, holding an optical element with an optical axis; a fixedpart, wherein the movable part moves relative to the fixed part and thefixed part comprises a bottom unit which is integrally formed, and thebottom unit comprises: a base member; a circuit member, located in thebase member; a driving coil assembly, electrically connected to thecircuit member and located in the base member, comprising: a connectionwire; a plurality of first driving coils, connected to each other viathe connection wire; and a plurality of second driving coils, locatedbetween the first driving coils and the circuit member; wherein whenviewed along a direction that is perpendicular to the optical axis, thesecond driving coils partially overlap the connection wire; wherein anumber of turns of each one of the first driving coils is different thana number of turns of each one of the second driving coils.
 2. An opticalelement driving mechanism, comprising: a movable part, holding anoptical element with an optical axis; a fixed part, wherein the movablepart moves relative to the fixed part and the fixed part comprises abottom unit which is integrally formed, and the bottom unit comprises: abase member; a circuit member, located in the base member; a drivingcoil assembly, electrically connected to the circuit member and locatedin the base member, comprising: a connection wire; a plurality of firstdriving coils, connected to each other via the connection wire; and aplurality of second driving coils, located between the first drivingcoils and the circuit member; wherein when viewed along a direction thatis perpendicular to the optical axis, the second driving coils partiallyoverlap the connection wire; wherein a width of the connection wire isgreater than a width of each one of the first driving coils.
 3. Anoptical element driving mechanism, comprising: a movable part, holdingan optical element with an optical axis; a fixed part, wherein themovable part moves relative to the fixed part and the fixed partcomprises a bottom unit which is integrally formed, and the bottom unitcomprises: a base member; a circuit member, located in the base member;a driving coil assembly, electrically connected to the circuit memberand located in the base member, comprising: a connection wire; aplurality of first driving coils, connected to each other via theconnection wire; and a plurality of second driving coils, locatedbetween the first driving coils and the circuit member; wherein whenviewed along a direction that is perpendicular to the optical axis, thesecond driving coils partially overlap the connection wire; wherein in adirection that is parallel to the optical axis, a size of the drivingcoil assembly is greater than a size of the circuit member.
 4. Anoptical element driving mechanism, comprising: a movable part, holdingan optical element with an optical axis; a fixed part, wherein themovable part moves relative to the fixed part and the fixed partcomprises a bottom unit which is integrally formed, and the bottom unitcomprises: a base member; a circuit member, located in the base member;a driving coil assembly, electrically connected to the circuit memberand located in the base member, comprising: a connection wire; aplurality of first driving coils, connected to each other via theconnection wire; and a plurality of second driving coils, locatedbetween the first driving coils and the circuit member; wherein whenviewed along a direction that is perpendicular to the optical axis, thesecond driving coils partially overlap the connection wire; wherein thebase member further comprises a first base and a second base, the firstbase is formed on the second base, a hardness of the first base isdifferent than a hardness of the second base, and the driving coilassembly is located at the first base, and the circuit member is locatedat the second base.
 5. The optical element driving mechanism as claimedin claim 4, wherein a top surface of the circuit member is in contactwith a bottom surface of the first base, a bottom surface of the circuitmember is in contact with the second base, and the top surface of thecircuit member is parallel to the bottom surface of the circuit member.6. The optical element driving mechanism as claimed in claim 5, whereinthe top surface of the circuit member and a top surface of the secondbase are in contact with the bottom surface of the first base.
 7. Anoptical element driving mechanism, comprising: a movable part, holdingan optical element with an optical axis; a fixed part, wherein themovable part moves relative to the fixed part and the fixed partcomprises a bottom unit which is integrally formed, and the bottom unitcomprises: a base member; a circuit member, located in the base member;a driving coil assembly, electrically connected to the circuit memberand located in the base member, comprising: a connection wire; aplurality of first driving coils, connected to each other via theconnection wire; and a plurality of second driving coils, locatedbetween the first driving coils and the circuit member; wherein whenviewed along a direction that is perpendicular to the optical axis, thesecond driving coils partially overlap the connection wire; wherein theoptical element driving mechanism further comprises an elastic element,wherein the movable part is elastically connected to the fixed part viathe elastic element, the bottom unit comprises an elastic elementconnection portion, and the elastic element passes through and iselectrically connected to the elastic element connection portion;wherein the elastic element connection portion comprises a firstperforation and a second perforation, and a size of the firstperforation is different than a size of the second perforation.
 8. Theoptical element driving mechanism as claimed in claim 7, wherein thefixed part further comprises a case, a plurality of straight lineportions and a plurality of curved line portions formed between the caseand the bottom unit, and the straight line portions are connected viathe curved line portions, wherein a width of each one of the curved lineportions is greater than a width of each one of the straight lineportions.
 9. An optical element driving mechanism, comprising: a movablepart, holding an optical element with an optical axis; a fixed part,wherein the movable part moves relative to the fixed part and the fixedpart comprises a bottom unit which is integrally formed, and the bottomunit comprises: a base member; a circuit member, located in the basemember; a driving coil assembly, electrically connected to the circuitmember and located in the base member, comprising: a connection wire; aplurality of first driving coils, connected to each other via theconnection wire; and a plurality of second driving coils, locatedbetween the first driving coils and the circuit member; wherein whenviewed along a direction that is perpendicular to the optical axis, thesecond driving coils partially overlap the connection wire; wherein thefixed part further comprises a case, the bottom unit further comprises asupport surface, the bottom unit is connected to the case via thesupport surface, and the support surface comprises a metal layer. 10.The optical element driving mechanism as claimed in claim 9, whereinwhen viewed along a direction that is perpendicular to the optical axis,the metal layer partially overlaps the circuit member or the drivingcoil assembly.
 11. An optical element driving mechanism, comprising: amovable part, holding an optical element with an optical axis; a fixedpart, wherein the movable part moves relative to the fixed part and thefixed part comprises a bottom unit which is integrally formed, and thebottom unit comprises: a base member; a circuit member, located in thebase member; a driving coil assembly, electrically connected to thecircuit member and located in the base member, comprising: a connectionwire; a plurality of first driving coils, connected to each other viathe connection wire; and a plurality of second driving coils, locatedbetween the first driving coils and the circuit member; wherein whenviewed along a direction that is perpendicular to the optical axis, thesecond driving coils partially overlap the connection wire; wherein thecircuit member comprises an external electrical connection surface whichis perpendicular to the optical axis, and the external electricalconnection surface is exposed from the bottom unit.
 12. An opticalelement driving mechanism as claimed in, comprising: a movable part,holding an optical element with an optical axis; a fixed part, whereinthe movable part moves relative to the fixed part and the fixed partcomprises a bottom unit which is integrally formed, and the bottom unitcomprises: a base member; a circuit member, located in the base member;a driving coil assembly, electrically connected to the circuit memberand located in the base member, comprising: a connection wire; aplurality of first driving coils, connected to each other via theconnection wire; and a plurality of second driving coils, locatedbetween the first driving coils and the circuit member; wherein whenviewed along a direction that is perpendicular to the optical axis, thesecond driving coils partially overlap the connection wire; wherein theoptical element driving mechanism further comprises a strengtheningmember located at the base member and integrally formed with the basemember, wherein when viewed along a direction that is perpendicular tothe optical axis, the strengthening member partially overlaps thedriving coil assembly.
 13. The optical element driving mechanism asclaimed in claim 12, wherein the strengthening member and the drivingcoil assembly are electrically independent.
 14. The optical elementdriving mechanism as claimed in claim 12, wherein when viewed along adirection that is parallel to the optical axis, the base memberpartially overlaps the strengthening member and the circuit member. 15.The optical element driving mechanism as claimed in claim 12, whereinthe strengthening member is made of a metal material, and thestrengthening member is a plate structure comprising a grid-shapedstructure, a honeycomb-shaped structure, or a concentric circle-shapedstructure.
 16. The optical element driving mechanism as claimed in claim12, wherein when viewed along a direction that is perpendicular to theoptical axis, a height of the strengthening member is the same as aheight of the driving coil assembly.
 17. The optical element drivingmechanism as claimed in claim 12, wherein the strengthening member isdisposed between the optical element and the driving coil assembly.